diff --git a/ProjectLiner/ProjectLiner/CollectionGenericObjects/ListGenericObjects.cs b/ProjectLiner/ProjectLiner/CollectionGenericObjects/ListGenericObjects.cs
index d37225b..a9066aa 100644
--- a/ProjectLiner/ProjectLiner/CollectionGenericObjects/ListGenericObjects.cs
+++ b/ProjectLiner/ProjectLiner/CollectionGenericObjects/ListGenericObjects.cs
@@ -58,20 +58,31 @@ namespace ProjectLiner.CollectionGenericObjects
             return _collection[position];
         }
 
-        public int Insert(T obj)
+        public int Insert(T obj, IEqualityComparer<T?>? comparer = null)
         {
-            if (Count >= _maxCount)
-                throw new CollectionOverflowException(Count);
+            if (Count == _maxCount) throw new CollectionOverflowException();
+            if (comparer != null)
+            {
+                if (_collection.Contains(obj, comparer))
+                {
+                    throw new ObjectAlreadyExistsException(obj);
+                }
+            }
             _collection.Add(obj);
             return Count;
         }
 
-        public int Insert(T obj, int position)
+        public int Insert(T obj, int position, IEqualityComparer<T?>? comparer = null)
         {
-            if (Count == _maxCount)
-                throw new CollectionOverflowException(Count);
-            if (position < 0 || position > Count)
-                throw new PositionOutOfCollectionException(position); ;
+            if (Count == _maxCount) throw new CollectionOverflowException();
+            if (position >= Count || position < 0) throw new PositionOutOfCollectionException();
+            if (comparer != null)
+            {
+                if (_collection.Contains(obj, comparer))
+                {
+                    throw new ObjectAlreadyExistsException(obj);
+                }
+            }
             _collection.Insert(position, obj);
             return position;
         }
diff --git a/ProjectLiner/ProjectLiner/CollectionGenericObjects/MassiveGenericObjects.cs b/ProjectLiner/ProjectLiner/CollectionGenericObjects/MassiveGenericObjects.cs
index 99f8a17..e8b40f5 100644
--- a/ProjectLiner/ProjectLiner/CollectionGenericObjects/MassiveGenericObjects.cs
+++ b/ProjectLiner/ProjectLiner/CollectionGenericObjects/MassiveGenericObjects.cs
@@ -61,8 +61,18 @@ namespace ProjectLiner.CollectionGenericObjects
             return _collection[position];
         }
 
-        public int Insert(T obj)
+        public int Insert(T obj, IEqualityComparer<T?>? comparer = null)
         {
+            if (comparer != null)
+            {
+                foreach (T? i in _collection)
+                {
+                    if (comparer.Equals(i, obj))
+                    {
+                        throw new ObjectAlreadyExistsException(i);
+                    }
+                }
+            }
             for (int i = 0; i < Count; i++)
             {
                 if (_collection[i] == null)
@@ -71,20 +81,29 @@ namespace ProjectLiner.CollectionGenericObjects
                     return i;
                 }
             }
-            throw new CollectionOverflowException(Count);
+            throw new CollectionOverflowException();
         }
 
-        public int Insert(T obj, int position)
+        public int Insert(T obj, int position, IEqualityComparer<T?>? comparer = null)
         {
-            if (position >= Count || position < 0)
-                throw new PositionOutOfCollectionException(position);
+            if (position >= Count || position < 0) throw new PositionOutOfCollectionException();
+
+            if (comparer != null)
+            {
+                foreach (T? i in _collection)
+                {
+                    if (comparer.Equals(i, obj))
+                    {
+                        throw new ObjectAlreadyExistsException(i);
+                    }
+                }
+            }
 
             if (_collection[position] == null)
             {
                 _collection[position] = obj;
                 return position;
             }
-
             int temp = position + 1;
             while (temp < Count)
             {
@@ -93,21 +112,19 @@ namespace ProjectLiner.CollectionGenericObjects
                     _collection[temp] = obj;
                     return temp;
                 }
-                temp++;
+                ++temp;
             }
-
             temp = position - 1;
-            while (temp > 0)
+            while (temp >= 0)
             {
                 if (_collection[temp] == null)
                 {
                     _collection[temp] = obj;
                     return temp;
                 }
-                temp--;
+                --temp;
             }
-
-            throw new CollectionOverflowException(Count);
+            throw new CollectionOverflowException();
         }
 
         public T? Remove(int position)
diff --git a/ProjectLiner/ProjectLiner/Exceptions/ObjectAlreadyExistsException.cs b/ProjectLiner/ProjectLiner/Exceptions/ObjectAlreadyExistsException.cs
new file mode 100644
index 0000000..8cbb498
--- /dev/null
+++ b/ProjectLiner/ProjectLiner/Exceptions/ObjectAlreadyExistsException.cs
@@ -0,0 +1,22 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Runtime.Serialization;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace ProjectLiner.Exceptions;
+
+/// <summary>
+/// Класс, описывающий ошибку, что в коллекции уже есть такой элемент
+/// </summary>
+[Serializable]
+public class ObjectAlreadyExistsException : ApplicationException
+{
+    public ObjectAlreadyExistsException(object i) : base("В коллекции уже есть такой элемент " + i) { }
+    public ObjectAlreadyExistsException() : base() { }
+    public ObjectAlreadyExistsException(string message) : base(message) { }
+    public ObjectAlreadyExistsException(string message, Exception exception) : base(message, exception)
+    { }
+    protected ObjectAlreadyExistsException(SerializationInfo info, StreamingContext context) : base(info, context) { }
+}